Inverse Variation

x and y vary inversely. Given (5, 20), what is the constant k?

• 4

• 5

• 25

• 100

Does the equation show an inverse variation? 
y=10/x

• yes

• no

Given the following equation, identify the constant k.
y = 54/x

• There is one.

• k = x

• 54

• y = k

Which of the following represents indirect variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

The cost per person to rent a mountain cabin is inversely proportional (varies inversely) to the number of people who share the rent. If the cost is $36 per person when 5 people share, what is the cost per person when 8 people share?

• $22.50

• $57.60

• $1.11

• $12.50

The time that a group of carpenters takes to build a deck is inversely proportional to the number of carpenters. If 3 carpenters can build a deck in 36 working hours, how many carpenters are needed to build a deck in 27 working hours?

• 2

• 3

• 4

• 5

• 6

What kind of variation is shown in the graph?

• Direct

• Inverse

The image is an example of the graph of a(n)

• direct variation

• inverse variation

• neither

• both

y varies inversely as x, if y = -3 when x = -6, find y when x = 14.

• 11

• -11

• 9/7

• 7/9

The speed r of a moving object is inversely proportional to the time t travelled is written as

• r = kt

• r = k/t

• t = kr

• t = r/k